Soft Start; Speed Reference Filter; Using The Zero Clamp Function - YASKAWA SGDH User Manual

8.5.4 Soft Start

The soft start function converts the stepwise speed reference inside the SERVOPACK to a consistent rate of
acceleration and deceleration.
Pn305 Soft Start Acceleration Time
Setting Range
Pn306 Soft Start Deceleration Time
Setting Range
The soft start function enables smooth speed control when inputting a stepwise speed reference or when selecting internally
set speeds. Set both Pn305 and Pn306 to "0" for normal speed control.
Set these parameters as follows:
• Pn305: The time interval from the time the motor starts until the motor maximum speed is reached.
• Pn306: The time interval from the time the motor is operating at the motor maximum speed until it stops.
Before soft start

8.5.5 Speed Reference Filter

Pn307 Speed Reference Filter Time Constant
Setting Range
This smoothens the speed reference by applying a 1st-order delay filter to the analog speed reference (V-REF) input. A
value that is too large, however, will slow down response.

8.5.6 Using the Zero Clamp Function

(1) Zero Clamp Function
The zero clamp function is used for systems where the host controller does not form a position loop for the speed
reference input. When the zero clamp signal (/ZCLAMP) is ON, a position loop is formed inside the SERVO-
PACK as soon as the input voltage of the speed reference (V-REF) drops below the motor speed level in the zero
clamp level (Pn501). The servomotor ignores the speed reference and then quickly stops and locks the servomo-
tor.
The servomotor is clamped within ±1 pulse of when the zero clamp function is turned ON, and will still return to
the zero clamp position even if it is forcibly rotated by external force.
Host controller
Setting Unit
0 to 10000
Setting Unit
0 to 10000
Maximum speed of Servomotor
After soft start
Setting Unit
0 to 65535 0.01 ms
When the /ZCLAMP signal is turned ON, a
speed reference below the Pn501 setting is detected.
YASKAWA SERVOPACK
Speed reference SGDH-
YASKAWA
V-REF
MODE/SET DATA/
CHARGE POWER
Zero clamp
/P-CON
(/ZCLAMP)
8-43
8.5 Operating Using Speed Control with Analog Reference
Factory Setting
ms 0
Factory Setting
ms 0
Pn305 Pn306
Factory Setting
40
Stops precisely!
Speed
Setting Validation
Immediately
Speed
Setting Validation
Immediately
Speed
Setting Validation
Immediately
8